176 



BLOOD AND LYMPH 



nutrients of the Ij'^mph in the space are exchanged for the 

 wastes of the cell. In this manner then the plasma of 



the blood tube becomes 

 lymph and is in turn passed 

 on into the tube, which 

 drains it away to other 

 parts of the body. 



Another feature of this 

 exchange is seen in the 

 action of the corpuscles. 

 It will be noted that the 

 red corpuscles do not leave 

 the blood tube, but the 

 white corpuscles or leu- 

 cocytes are able to pass 

 through tiny spaces in the 

 walls. The reason for this 

 is that the leucoc5d;es are 

 able to change their shape 

 and to push themselves 

 through holes too small 

 to let the rigid red corpus- 

 cles pass. Certain proteids 

 which are not dialyzable 

 also probablj' pass through 



Fig. C2 — The lymphatic system ; a, union similar SpaCCS in the blood 



of left jugular and subclavian veins, and , i ii u -Clj. 



poiut of union with the thoracic duct, tUOe WallS Dy llltratlOn. 

 i; c, right jugular and subclavian veins, Another featUTC tO be 



and point of union of right lympliatic 



system ; d, receptacle for food absorbed Considered in this diagram 



fron^ ae intestine ; the oval bodies are j^ ^^^ dispOSal of the WasteS. 



If the liquids were station- 

 ary the exchange would go on until all reached the same 



